BB-8 is an astromech droid and one of the main characters in the Star Warssequel trilogy. Carrying part of a map that leads to Luke Skywalker, he is forced to part with Poe Dameron, his master and close friend. He travels across the deserts of Jakku in order to keep the map out of the hands of the First Order.
Accompanying Poe Dameron on Jakku, BB-8 meets Lor San Tekka and receives a data chip containing the whereabouts on the lost Jedi Luke Skywalker. However, the village they are in is discovered and attacked by Kylo Ren and several Stormtroopers of the First Order. When Poe's ship is damaged while attempting to escape, Poe stays behind to protect the villagers and sends BB-8 away from the battle with the information in tow.
BB-8 eventually meets Rey, who reluctantly lets him tag along with her. When the First Order returns to Jakku searching for the map, the pair escapes with Finn in the Millennium Falcon. Finn confides with BB-8 over his past affiliation as a Stormtrooper and convinces BB-8 to direct them to the Resistance base. The group run into Han Solo and Chewbacca, who take them to Takodana. There, Rey and BB-8 discover the lightsaber of Luke Skywalker. Upon touching it, Rey becomes frightened by a vision and runs off into the wood, with BB-8 following her. The First Order attacks shortly after, prompting Rey to have BB-8 leave her to avoid being spotted. Following the Battle of Takodana, BB-8 returns to the Resistance base on D'Qar and is reunited with his master. He eventually finds an inactive R2-D2, curious over the latter's current condition and wondering if R2-D2 had the rest of the map in his backup memory, with C-3PO replying that it was unlikely.
BB-8 then participates in the battle at Starkiller Base, accompanying Poe on his T-70 X-wing. After the battle, the two return D'Qar. Upon arrival, R2-D2 awakens and reveals that he had the map to Luke's location, with the part that BB-8 was carrying completing it and showing where Luke was. With the knowledge of Luke's whereabouts, BB-8 and the rest of the Resistance bid farewell to Rey, Chewbacca, and R2-D2 as they set off to find Luke.
BB-8 continues serving the Resistance. He accompanies Poe on his T-70 X-wing during the Battle of of D'Qar while the members of the Resistance try to evacuate their base. Poe decides to attack the Mandator IV-class Siege Dreadnought Fulminatrix to buy time for the evacuation and BB-8 helps him fixing the the X-wing's weapon systems when they go offline. After the battle, they return to the Resistance ship, the Raddus, and BB-8 tells Poe that Finn is finally awake. Shortly after, Kylo Ren fires on the hangar of the Raddus, destroying Poe's X-Wing. Finn, Poe and BB-8 witness the destruction, and the explosion knocks out BB-8's head off his body, though he manages to put himself together right after.
Later, BB-8 goes with Finn and Rose to their mission on Canto Bight to find the master codebreaker. At the cassino, a drunken alien called Dobbu Scay thought that BB-8 was a sloting machine, so he started to put coins inside him. Then, Rose, Finn and BB-8 are arrested for parking their shuttle illegally, and the officers throw the droid, who is now heavy with coins, out of the cassino. In the prison cell, the trio meets a hacker called DJ who offers them his help. DJ breaks them of of the cell, and when the guards approach to confront them, BB-8 launches all the coins he has inside him on one of the guards. After Rose and Finn freeded the fathiers, BB-8 and DJ steal a ship to pick up them, so they can leave the planet.
When the group goes undercover on board the Supremacy, Finn puts a garbage receptacle over BB-8 to disguise him, and the droid attempts to imitate the sounds of a repair droid to go unnoticed. However, the First Order droid BB-9E is able to see through their disguise and reports them to the First Order, resulting in the capture of the group, except for BB-8. After the Supremacy was split in two because of the sacrifice of Vice Admiral Amilyn Holdo, Captain Phasma and a group of stormtroopers are about to attack Finn and Rose, but they are all surprised when a First Order AT-ST starts to fire on the troopers. When troopers manage to partly destroy the cockpit of the walker, it is revealed that BB-8 had hijacked the vehicle and was piloting to help Finn and Rose, who look at the droid stunned. After Finn fought and defeated Phasma, he and Rose get in the First Order AT-ST that BB-8 is piloting, and the walker carries them to a First Order shuttle.
After the trio escaped the Supremacy, they crash their shuttle at the Resistance base on Crait. Poe and the others are alarmed upon seeing a First Order shuttle but Finn and Rose soon reveal themselves, and Poe asks for BB-8. The droid immediataly runs to Poe who embraces him and says that he is very glad to see his friend again. BB-8 then helped the Resistance by analysing the schematics of the base, reaveling that the only way out is the entrance that is being blocked by the First Order attack. However, later the group, including BB-8, follow the vulptices that had found another way out of the cave. After Rey arrived to find the Resistance members, she lifts the boulders blocking their exit and helps everyone get aboard the Millennium Falcon. Inside the Falcon, BB-8 reunites with Rey, and she touches his antenna saying that it looks good.
After learning of the Final Order and wayfinders, BB-8 accompanied Rey, Finn, Poe, Chewbacca and C-3PO to Pasaana to find a Sith wayfinder where they encountered Lando Calrissian. During his time on Passanna the group recovered a Sith dagger. On the Bestoon Legacy, BB-8 found a little droid named D-O and recharged his batteries. The group headed to Kijimi to have the Sith text extracted from C-3PO's memory. The process wiped the droid's memory, but revealed coordinates to a wayfinder on a moon in the Endor system. The Resurgent-class Star Destroyer Steadfast later arrives at Kijimi, and Rey sensed that Chewbacca was alive and the group mounted a rescue mission. The group traveled to Kef Bir where BB-8 and D-O interacted with some orbaks. Later, BB-8 joined the Resistance ground forces during the Battle of Exegol. After the battle, BB-8 accompanied Rey to Tatooine and visited Luke's old abandoned home and buried Anakin's and Leia's lightsabers there, having built her own.
The very first concept art of R2-D2 in the early 1970s depicted him in an almost identical fashion to BB-8. However, due to technological disadvantages at the time, the creators of the movie were forced to use R2's final look instead.
BB-8 was a fully-functional prop on the set of Episode VII, with no CGI used on the character at all.